The technique is also called dark field microscopy and live blood cell analysis. A search engine of the terms will bring up lots of sites, but most of them offer equipment for sale or explain how the dark field microscope works. I have yet to find a site that explains diagnoses, which if you studied biology in school can be simple to understand. This site is about the only one I could find that explains the technique simply and gives some examples:
The technique is so simple but so effective.